驱动模式控制的双功能、融合式电致变色/发光器件

Organic Electrochromic Devices (OECD) and Organic Light Emitting Devices (OLED), both have their own properties and different application circumstances. Dual functional device with the characteristics of two devices, is very attractive for the application for new generation displays and smart windows etc. The conventional “combination” of two devices by stacking or taping OECD and direct current-driven OLED together, leads complicated processing procedures and high optical loss. In this project, we propose to use an alternating current-driven OLED (ACOLED) as a component for the dual-functional device due to its structural similarity to OECD. A simplified single merged structure of the dual functional device providing low optical losses is introduced. The insulated and semiconducting layers of the device will be modified to satisfy the working conditions of both electrochromics and electroluminescense. Consequently, the dual-functionality can be achieved by switching between driving voltage modes. The electrochromic functionality is realized by direct current loading, while electroluminescence functionality is achieved by alternating current loading. Moreover, the working mechanism of the carriers and ions will be studied to optimize performance of the device. The project focuses on a unique merged device structure to realize dual functions with both advantages of OECD and ACOLED, which has broad application, and offers a brand-new design concept for multifunctional devices.

有机电致变色器件（OECD）与有机电致发光器件（OLED），具有各自特点和适用场景。集两者优势的电致变色/发光双模式器件，在显示、节能型智能窗等领域具有广泛的应用前景。目前电致变色/发光双功能器件所采取的常规“组合”集成式，如直接将OECD和直流OLED相垛堞、粘贴，结构复杂，光学损耗大。本项目采用交流OLED（ACOLED），科学巧妙的利用它与OECD结构相似这一特性，设计了结构简单的双功能融合式器件。基于两者不同的工作机制，调整器件内绝缘层和半导体层的材料以及掺杂方式，达到单层薄膜双功能，继而单一器件双功能的目的。器件利用驱动方式控制其工作模式，实现直流驱动电致变色，交流驱动电致发光。在此基础上，深入理解载流子注入、平衡以及离子行为，进一步优化器件性能。本项目独特的融合型结构设计，实现了互补性极强的双功能器件，大大扩展了其应用领域，同时融合式结构理念为今后双功能器件设计提供新的思路。

项目围绕电致变色和发光器件功能性融合这一研究目标，针对项目直流驱动电致变色以及交流驱动电致发光功能融合过程遇到的问题，提出一系列有效的解决方案：1）前期研究中发现一部分小分子有机材料在中性状态光致/电致发光;不同带电离子状态下吸收谱移动的独特光学性质。我们理论计算与实验结合，讨论了小分子内给-受体结构调节对其光学性能的影响。基于此研究思路，我们也尝试从理论计算上理解PAH小分子体系内面结构变化对其电致发光以及不同离子态吸收谱（即电致变色）的影响。2）交流驱动电致发光器件的主体发光层若采用主-客体掺杂策略，要求主体有机导电聚合物带隙应大于客体发光材料（一般为小分子）。目前主流的有机导电聚合物材料的带隙一般在2.0 eV左右，不能满足本项目对有机聚合物宽带隙的要求。我们采用化学合成法制备的独特的立体蝶状单体进行电化学聚合，得到了带隙为3. 1 eV的宽带隙聚合物材料。工作继而总结以及提出了宽带隙聚合物结构设计的新思路。3）我们独辟蹊径，提出电解质层除了具有离子传导的功能外，还可具有颜色调控的功能。采用“调色板”策略实现了对器件颜色的精准调控，赋予多色彩电致发光-变色融合式器件制备方式上极大的自由度和灵活性。